I switched to CM Eclair ROM recently and am forced to live without the Sense UI. Here’s my list of must have android apps (the order is not significant):
Dialer One – The best Sense dialer replacement.
Dropbox – I have it on all my internet connected devices.
Meebo IM – Used for facebook chat.
SyncMyPix – Sync contacts with facebook
Facebook for Android
988 Pomocnik – Serbian CallerID
TV Vodic – TV Guide, Serbian version
Calling Flip – flip to phone while ringing to turn of the ringtone.
In-app Wifi Toggle – turn on wifi from any app